> ## Documentation Index
> Fetch the complete documentation index at: https://docs.apollodeploy.com/llms.txt
> Use this file to discover all available pages before exploring further.
# What test mode proves
> Use Signal test mode without confusing validation success with real delivery
Set `testMode` to `true` on a send request to exercise Signal's send flow without delivering to real recipients.
The resulting email record uses the `test` status unless an explicit supported test outcome is requested through Signal's test-address behavior.
## Test mode can verify
* Your API key authenticates to the intended project.
* The key has `emails:send`.
* Required fields and address shapes pass validation.
* The From address belongs to a domain Signal accepts for the project.
* The content, metadata, tags, tracking overrides, and attachment structure are accepted.
* Your integration receives and stores the Signal response shape.
* The request appears in Signal's email record and customer-visible diagnostics.
## Test mode cannot verify
* A provider accepted a real message.
* A recipient mail server accepted it.
* DNS changes have propagated to every resolver.
* A message reached the inbox instead of spam.
* Tracking links and pixels behaved in a real mailbox.
* Your production recipient consent and suppression inputs are correct.
## Recommended progression
1. Use test mode while implementing the request and response contract.
2. Confirm the record reaches `test` and inspect its content and metadata.
3. Send one controlled real message to an inbox you own.
4. Follow `sent` and `delivered` separately.
5. Test only the tracking features actually enabled for the project.
6. Verify webhook signature handling with a webhook test event before relying on production events.
A `test` message is deliberately not a delivery test.
Do not use it as evidence of provider handoff, recipient-server acceptance, inbox placement, opens, or clicks.
Review the dashboard and API test workflows.